This invention relates in general to a mixing apparatus for mixing fluid flows in a combustion engine, and more particularly to a mixing apparatus for mixing recirculated exhaust gas in a combustion engine.
Exhaust gas recirculation (EGR) is a known method that is used to reduce the Nitrogen oxide (NOx) emissions in internal combustion engines. A conventional EGR system includes a control valve, also referred to as an EGR valve, that regulates the amount of exhaust gas that is taken from an engine exhaust manifold and which is mixed with intake air for recirculation back to the engine via an engine intake manifold.
The EGR valve is located on an associated component of the engine, typically at a point directly upstream of the intake manifold of the engine. The EGR valve is a valve which opens a passageway between the exhaust and intake manifold to allow a specific amount of the engines exhaust gas to recirculate back to the combustion cycle of the engine. The recirculation provided by the EGR valve helps to reduce combustion temperatures thereby reducing or preventing the formation of NOx emissions. NOx emissions are primarily formed when a mixture of nitrogen and oxygen is subjected to high temperatures.
The recirculated exhaust gas is typically mixed with incoming fresh air in an EGR mixer prior to introduction back into the engine combustion cycle. The flow characteristics of the exhaust gas as it enters and moves through the EGR mixer affects the efficiency of mixing with the incoming fresh air. Adequate mixing of the exhaust gas with the incoming fresh air may avoid performance degradation and help to minimize mixing losses in order to avoid fuel consumption penalties.
Although numerous designs and configurations of EGR mixers have been developed in the past, it would be beneficial to provide an improved mixing apparatus that reduces component weight and increases the ease of manufacturing the mixing apparatus and assembling the mixing apparatus within the EGR system.